In recent years, as computers become faster and hard disc capacity increases, volume of data which can be dealt with has increased. In response to this, large-capacity recording media are now in increasing demand and DVD-Rs have therefore been developed as large-capacity recordable CDs. Various types of dyes, including cyanine dyes and metal chelate dyes, have been proposed for use in the recording layer of DVD-Rs. A number of optical media have been proposed which use metal chelate dyes that are excellent in light-resistance and weather-resistance among these dyes (See Patent Document 1).
In addition, there is a report about an azo-metal chelate dye consisting of a metal and an azo dye compound, where the azo dye compound is formed of a diazo component including nitrogen atoms and a coupler component including a fluorine-substituted alkylsulfonylamino group (See Patent Document 2). Moreover, there is a report to the effect that the recording characteristics of an optical recording medium, such as light-resistance and durability, can be improved by using an azo-metal chelate dye as a recording layer of the optical recording medium. Here, the azo-metal chelate dye consists of a metal and an azo dye compound which includes a coupler component where an amino group on a benzene ring forms a fused heterocycle (See Patent document 3).    Patent Document 1: Japanese Patent Laid-Open No. Hei03-268994 (JP3-268994)    Patent Document 2: Japanese Patent Laid-Open No. Hei11-166125 (JP11-166125)    Patent Document 3: Japanese Patent Laid-Open No. 2000-309722 (JP2000-309722)